Daylight control system, device and method

ABSTRACT

A system and device for and a method of programming and controlling light fixtures is disclosed. A system in accordance with the present invention includes a stationary controller unit that is electrically coupled to the light fixtures. The stationary controller unit is configured to be remotely programmed with a portable commissioning device to automatically control the lights fixtures. The stationary controller unit and the portable commissioning device include light sensors, micro-computers and transceivers for measuring light levels, running programs, storing data and transmitting data between the stationary controller unit and the portable commissioning device. In operation, target light levels selected with the portable commissioning device and the controller unit is remotely programmed to automatically maintain the target level.

RELATED APPLICATIONS

This application is a continuation application of the co-pending U.S.patent application Ser. No. 11/657,427 titled “DAYLIGHT CONTROL SYSTEM,DEVICE AND METHOD”, filed Jan. 23, 2007, which is a continuationapplication of U.S. patent application Ser. No. 10,925,455 titled“DAYLIGHT CONTROL SYSTEM, DEVICE AND METHOD”, filed Aug. 24, 2004, nowU.S. Pat. No. 7,190,126. The co-pending U.S. patent application Ser. No.11/657427 titled “DAYLIGHT CONTROL SYSTEM, DEVICE AND METHOD”, filedJan. 23, 2007 and the U.S. Pat. No. 7,190,126 are both herebyincorporated by reference.

GOVERNMENT FUNDING

This invention was developed under Contact No. 500-01-041 with theCalifornia Energy Commission. The Government may have certain rights tothis invention.

FIELD OF THE INVENTION

This invention relates to light management systems, devices and methods.More particularly, the invention relates to a system and device for anda method of remotely 10 programming and controlling room lights.

BACKGROUND OF THE INVENTION

Because of rising energy costs and negative environmental impacts ofenergy usage and energy generation, there is a continual effort toreduce energy consumption of lighting fixtures, especially in largepublic and private building. A number of different light managementsystems have been developed to help reduce power consumption. One typeof light management system utilizes motion detectors or sensors thatshut light fixtures on and off based on detected motion. Other lightmanagement systems use light sensors, whereby light output levels fromlight fixtures are automatically adjusted based on detected levels oflight. There are still a number of shortcomings with currently availablelight management systems and problems with integrating lightingequipment from different light management systems.

To ensure that the manufactures of lighting equipment, installers of thelighting equipment and the end users of the lighting equipment make,install and use the lighting equipment to meet the lighting requirementsof the environment while operating as efficiently as possible, energyregulators require product documentation as well as on-site operationalor performance data of the lighting equipment. Typically, the on-siteoperational or performance data requires that the light output from eachof the light fixtures installed are individually measured and documentedto generate what is referred to herein as a commissioning report. Inlarge office buildings with thousands of light fixtures, generating acommissioning report is extremely time consuming and labor intensive.

With the complexity of modem light management systems and the continuedpressures to reduce energy consumption. there is a continued need tofind improved systems and devices for and methods of integration oflight management equipment that also provide operational or performancedata to show that light fixtures are operating effectively andefficiently.

SUMMARY OF THE INVENTION

The present invention is directed to a device and a system forcontrolling lights in response to a secondary light source, such asdaylight. The present invention provides a user friendly device andsystem for and method of commissioning lighting control zone. Lightingcontrol zones can include a large number of light fixtures, such as aretypically found in large public and private buildings. The device,system and method of the present invention also provide a reliable andsimple way to provide performance data, history data and set-up data,also referred to as operating data, for the lighting control zones.

In accordance with the embodiments of the invention, a stationarycontroller unit includes a light sensor and a communication means. Thestationary controller unit is configured to control lights to operate attarget output levels. The stationary controller unit is also referred toherein as a controller unit and it is understood that the controllerunit is stationary. In accordance with a preferred embodiment of theinvention, the controller unit is configured to be programmed with aportable commissioning device, as described in detail below. Theportable commissioning device is also referred to as a commissioningdevice and it is understood that the commissioning device is portable.

In accordance with the embodiments of the invention, the commissioningdevice also includes a light sensor measuring illumination and acommunication means, such that the controller unit and the commissioningdevice can participate in two-way communication to transfer operationaldata from the controller unit to the commissioning device and remotelyrun commissioning programs and calibration programs on the controllerunit from the commissioning device, as described below. Thecommissioning device is preferably powered with a portable energysource, such as a battery, a solar cell or a combination thereof. Wherethe commissioning device is powered with the battery, the commissioningdevice can include electrical contacts and/or connectors to electricallycouple to a battery charger.

To commission light fixtures, a target light level is selected from thecommissioning device through a user interface and the commissioningdevice instructs the controller unit to run a commissioning program. Theuser interface can include any number of input mechanisms and displaysincluding, but not limited to, buttons, knobs, lights and screens.Preferably, the user interface includes buttons and an LED screen forselecting input values and for migrating through menus and/or programs.

The target light level that is selected from the commissioning device ispreferably based on the lighting requirements for the environment beingcommissioned, which can include light levels required or suggested foroffices, schools and the like by federal, state or local governments. Inorder to program the controller unit to maintain the selected targetlight level, room light of the area being commissioned is measured usingthe light sensor of the commissioning device, also referred to as thecommissioning device light sensor. Preferably, the room light ismeasured in a work plane (i.e. between 2 to 4 feet from the floor of theroom), where occupants generally work or most often experience thelighting conditions of the room. The room light that is measuredincludes natural room light (light from windows and/or outdoors), lightthat floods into the room from adjacent rooms, as well as light that isemitted from the light fixtures being commissioned.

After the room light is measured, the controller unit varies a controlsignal applied to the light fixtures to adjust the light outputs fromthe light fixtures to meet the selected target light level. The lightsensor from the controller unit, also referred to as the controller unitlight sensor, is then programmed or set to adjust the control signalapplied to the light fixtures to adjust light output levels to maintainthe selected target light. For example, when the room becomes exposed tomore natural light, the controller unit will vary a control signalapplied to the light fixtures to automatically decrease the lightoutputs from the light fixtures, such that the light level at the tasklevel and as measured by the controller unit light sensor remainssubstantially constant. Conversely, as the room is exposed to lessnatural light, the controller unit will vary the control signals appliedto the light fixtures to automatically increase the light outputs fromthe light fixtures to maintain the target light level in the room. Thecontroller unit and the commissioning device light sensors arepreferably photodiodes light sensors that include filters to match aphotopic response curve (response to day light as perceived by the humaneye). These light sensors are typically sensitive to a spectrum of lightthat includes light having wavelengths in a range of 380 to 750nanometers. The light senor that is used in the control unit preferablyhas a response that is less than a cosine corrected response.

The controller unit and the commissioning device both preferably includemicroprocessors with sufficient logic circuitry and memory to store, runand execute programs and store operational data, such as describedbelow.

As described above, the controller unit and the commissioning devicepreferably participate in two-way communication to run programs, such asthe commissioning program described above and a calibration program,such as described below. Further, two-way communication allows thecontroller unit and the commissioning device to exchange performancedata, history data and set-up data, all of which can be used to generatecommissioning reports. Commissioning reports can be used to providedocumentation to a building authority and/or energy commission that thelight fixtures are operating to provide sufficient light levels for theoccupants and are operating at sufficiently low energy consumptionlevels.

Preferably, two-way communication between the controller unit and thecommissioning device is wireless and uses infrared transceivers.Alternatively, two-way communication between the controller unit and thecommissioning device is wireless and uses radio transceivers.Preferably, the commissioning device is configured with means todownload data to a personal computer, data such as light fixtureidentification numbers and locations, light fixture set up parametersand/or operation history. The means to download is an infraredtransmitter, a USB connection, or any other suitable networkingconnection. Accordingly, the commissioning report can be formatted andprinted from the personal computer.

Many of the light fixtures in office, manufacturing and educationalenvironments use ballasts and fluorescent light bulbs, generallyreferred to herein as fluorescent light fixtures. Fluorescent lightfixtures do not have linear or uniform output responses to voltagesapplied. Accordingly, programming the controller unit to maintain agroup of fluorescent light fixtures using a single voltage response orprofile in response to changes in detected light levels can result ininefficient operation of the fluorescent light fixtures as well asuneven lighting throughout the work-space. To address this problem, thecommissioning device of the present invention is preferably configuredto run a calibration program from the controller unit to calibrate a“dimming response” for the fluorescent light fixtures. The controllerunit can then be programmed to maintain the fluorescent light fixtureoutputs in accordance with a calibrated or corrected dimming response.

To determine a dimming response for fluorescent light fixtures or agroup of fluorescent light fixtures, the commissioning device instructsthe controller unit by the wireless means running the calibrationprogram. During the calibration process or during the execution of acalibration program, the controller unit places the fluorescent lightfixture or group of fluorescent light fixtures at full power output.Then the fluorescent light fixture or group of fluorescent lights isswitched on and off as well as dimmed through a range of reduced appliedvoltages, referred to herein as a dimming sequence. While running thedimming sequence, light outputs generated from the fluorescent lightfixture or group of fluorescent light fixtures is measured using one ormore of the controller unit and commissioning device light sensors. Fromthe measured light outputs through the range of applied voltages, adimming response is calculated. From the calculated dimming responses ofthe fluorescent light fixture or group of fluorescent light fixtures,the controller unit is programmed to maintain the light output from thefluorescent light fixture or group of fluorescent light fixtures with acorrection algorithm or compensation factor to account for any responsediscrepancies measured against a standard or ideal dimming response.Accordingly, all of the fluorescent light fixtures or groups offluorescent light fixtures commissioned in a work-space will maintainthe target light levels, while exhibiting a consistent dimming responseto provide efficient and uniform lighting throughout the work space.

In accordance with the system of the present invention, a controllerunit is configured to control, operate and maintain a group of lightfixtures. The controller unit can be programmed to control, operate andmaintain the entire group of light fixtures according to single set ofparameters or, alternatively, control, operate or maintain sub-groups ofthe group of light fixtures according to a separate or unique set ofparameters. The controller unit adjusts the light outputs of thecontrolled lights using control signals. Control signals can include,but not limited to, DC voltage control signals, digital control signalsand radio or wireless control signals. The system of the presentinvention also preferably includes a power pack that includes a relayswitch that is rated for high voltage operation and that is used toswitch the controlled lights on and off. The system of the presentinvention also preferably includes one or more motion detectors oroccupancy sensors for operating light fixtures within the group based ondetected occupancy. In accordance with further embodiments of theinvention, the system includes one or more manual switches for manuallycontrolling light fixtures within the group of light fixtures. Devices,such as motion sensors or occupancy sensors and manual switches arereferred to herein as override devices since they can override lightingprograms running from the controller unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic representation of the commissioning device, inaccordance with the embodiments of the invention.

FIG. 2 shows a schematic representation of a portion of a lightmanagement system that includes a controller unit, in accordance withthe embodiments of the invention.

FIG. 3 shows a schematic representation of system, in accordance withthe embodiments of the invention.

FIG. 4 shows a detailed schematic representation of a light managementssystem, in accordance with the embodiments of the invention.

FIG. 5 shows a wiring schematic of a light management system thatincludes override devices, in accordance with the embodiments of theinvention.

FIGS. 6A-B are block flow diagrams outlining steps for commissioninglight fixtures and for calibrating light fixture dimming responses, inaccordance with the a method of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a light management system thatincludes a portable commissioning device that correlates light sensordetection from a working plane with the commissioning device to thelight sensor detection from a stationary controller unit, preferablymounted to a ceiling of a room. The system also provides for two-waycommunication between the commissioning device and the controller unitto automate the generation of commissioning reports. Further, the systemprovides for the ability to program the controller unit to operate thelight fixtures with a corrected or calibrated dimming response and thusmaintain preferred task illumination levels.

FIG. 1 shows a schematic representation a portable commissioning device100, in accordance with the embodiments of the invention. The commissiondevice 100 is configured for commissioning light fixtures to provide atarget light level. The commissioning device 100 includes a light sensor103, a micro computer 105, a transceiver 115 and power portable powersupply 111, such as a battery and/or solar cell. The light sensor 103 ispreferably an LED light sensor. The transceiver 115 is preferably aninfrared transceiver for providing two-way communication between thecommissioning device and a controller unit, such as described withreference to FIG. 2 below.

Still referring to FIG. 1, the commissioning device 100 also includes auser interface 106 that can include buttons 109 and an LED screen 107for selecting input values and for migrating through menus and/orprograms that are stored on and run from the micro-computer 105. Inaccordance with a preferred embedment of the invention, thecommissioning device 100 includes a connection 113 for downloadingoperational data to a personal computer 125 for generating commissioningreports therefrom. The connection 113 is an infrared transmitter, a USBconnection or any other suitable networking connection.

FIG. 2 shows a schematic representation of a portion of a light controlsystem 200, in accordance with the embodiments of the invention. Thesystem 200 includes a controller unit 201 that is electrically coupledto at least one ballast 211 and is configured for controlling thecontrol signal applied to a light source (not shown) through the ballast211. The controller unit 201 includes a light sensor 203 for sensing andmonitoring room light levels in the room.

Still referring to FIG. 2, the controller unit 201 also includesmicro-computer 207 for running lighting programs, running commissioningprograms and calibration programs, such as described above and below.The micro-computer 207 also stores operational data that can betransmitted to the commissioning device 100 (FIG. 1) by a compatibletransceiver 205, that is preferably an infrared transceiver or,alternatively, a radio transceiver. Preferably, the controller unit 201also includes a low-voltage power supply 209 for powering the lightsenor 203, the transceiver 205 and the micro-computer 207.

FIG. 3 is a schematic representation of system 300, in accordance withthe embodiments of the invention. The system 300 includes a portablecommissioning device 200, such as described above with reference toFIG. 1. The system 300 also includes a controller unit 201, such asdescribed above with reference to FIG. 2. The controller unit 201 iselectrically coupled to a plurality of ballasts 302, 304 and 306 forcontrolling the control signal applied to a corresponding plurality offluorescent light fixtures 301, 303 and 305. The controller unit 201 andthe commissioning device 200 are configured to provide two-waycommunication between each other, as indicated by arrow 311, usingtransceivers (not shown). The two-way communication between thecontroller unit 201 and the commissioning device 200 allows programs tobe executed on the controller unit 201 from the commissioning device 200and also allows the transmission of operational data from the controllerunit 201 to the commissioning device 200 that can then be used togenerate a commissioning report.

In accordance with further embodiments of the invention, the system 300includes one or more override devices 309 that can override or interruptlighting programs running from the controller unit 201 and directlyoperate the fluorescent lights 301, 303 and 305. The one or moreoverride devices 309 can include a dimmer switch and a motion sensor oroccupancy sensor, such as described below with reference to FIGS. 4 and5.

FIG. 4 shows a detailed schematic of light management system 400, inaccordance with the embodiments of the invention. The light managementsystem 400 includes a controller unit 431 coupled to any number of lightfixtures (not shown) through one or more ballasts 441. The controllerunit 431 is preferably coupled to a low-voltage power source 421 forpowering components of the controller unit 431, such as a light sensor435, an infrared transceiver 433 and a micro-computer (not shown). Thecontroller unit 431 is preferably electrically coupled to at least onewall switch 451 that can override a lighting program running on thecontroller unit 431 and directly control the control signal applied tothe light fixtures through the ballasts 441.

Still referring to FIG. 4, the system 400 also includes a portablecommissioning device 401 that is powered with a battery (not shown) andis configured to remotely program the controller unit 431 to regulatethe light outputs according to a lighting program. The commissioningdevice 401 has a user interface 406 that includes a display 407 andbuttons 409 for selecting input values and for migrating through menusand/or programs that are stored on the controller with 431 and/or thecommissioning device 401. The commissioning device 401 also preferablyincludes a USB port 413 for connecting to and downloading operationaldata to personal computer 125, as indicated by the arrow 419.

The commissioning device also includes a light sensor 403 for measuringroom light and an infrared transceiver 405 for providing two-waycommunication between the commissioning device 401 and the controllerunit 431, as indicated by the arrows 432 and 432′ through the compatibleinfrared transceiver 433 of the controller unit 431.

FIG. 5 shows a wiring schematic of a light management system 500 thatincludes override devices 507 and 511, in accordance with theembodiments of the invention. The system includes a portablecommissioning device 501 and a stationary controller unit 503, such asdescribed in detail above. The controller unit 503 is coupled to one ormore ballasts through a power line 509 to adjust the control signalapplied to light fixtures through the one or more ballasts. Thecontroller unit 503 is also electrically coupled to a power-pack 513that is connected to a power line 512. The power-pack 513 is configuredto provide low-voltage power to the controller unit 503 and the overridesensor 507 that is preferably an occupancy sensor or a motion sensor.The power-pack 513 is configured to switch the controlled light on andoff with a relay switch rated for high voltage use. The system alsopreferably includes a dimmer switch 511 that is electrically coupled tothe controller unit 503 for adjusting the control signal applied to thelight fixtures.

FIG. 6A is a flow diagram 600 outlining steps for commissioning lightfixtures, in accordance with the method of the present invention. In thestep 601, a target light level for a room is selected. Preferably, thetarget light level for the room is selected from a portablecommissioning device that is running a commissioning program or acommissioning sequence. The target light level for the room is, forexample, selected through a user interface on the commissioning device,such as described in detail above. After the target level of light isselected in the step 601, in the step 603 the room light is measured ormonitored using a commissioning device light sensor. Preferably, theroom light is measured or monitored in the step 603 at a work plane ofthe room, such as on a desk-top where the lighting requirements are mostimportant for occupants of the room. While monitoring the room light inthe step 603, in the step 605 a control signal that is applied to thelight fixture or light fixtures is adjusted such that the output fromthe light fixture or light fixtures meets the target light level. Afterthe light output from the light fixture or light fixture is adjusted tomeet the target light level for the room in the step 605, in the step607 the controller unit light sensor is programmed or set toautomatically adjust the control signal applied to the light fixture orlight fixtures in order to maintain the target light level for the room.Accordingly, when the room becomes exposed to more natural light, thecontroller unit will vary the voltage applied to the light fixture orlight fixtures to automatically decrease the light output from the lightfixture or light fixtures, such that the task illumination as measuredby the controller unit light sensor remains substantially constant. Ifenough daylight is available, the controller unit can switch thecontrolled lights off through a power-pack, such as described above.Conversely, as the room is exposed to less natural light, the controllerunit will vary the control signal applied to the light fixtures toautomatically increase the light output from the light fixture or lightfixtures to maintain the target light level in the room. Also, if thecontrolled lights are turned off, then the controller unit can switchthe controlled light on through the power-pack. After the controllerunit light sensor is set to maintain the target light level for the roomin the step 607, in the step 609 a commissioning report can begenerated. The commissioning report can include any operational dataincluding, but not limited to, light fixture identification numbers,set-up parameters (e.g., target light level set points), light fixturelocations and or performance characteristics (e.g., dimming responsedata). As described above, the operational data can be downloaded fromthe portable commissioning device to a personal computer where thecommissioning report is formatted and printed.

FIG. 6B is block flow diagram 650 outlining steps for calibrating lightfixture dimming responses, in accordance with the methods of the presentinvention. At any time during, after or before executing a commissioningprogram or commissioning sequence, a calibration program or calibrationsequence can be executed. While running the calibration program orcalibration sequence in the step 651, the light fixture or group oflight fixtures is operated through a range of applied voltages and thecorresponding light outputs are measured. Preferably, in the step 651the light fixtures are operated to full power and are then operatedthrough a range of reduced applied voltages while measuring thecorresponding light outputs. The corresponding light outputs can bemeasured with a commissioning device light sensor, the controller unitlight sensor or a combination thereof. From the range of appliedvoltages and the corresponding light outputs, in the step 653 a dimmingresponse curve and/or a correction factor is calculated. After, thedimming response curve and/or the correction factor is calculated in thestep 653, in the step 655 the controller unit is programmed toautomatically control the light fixtures in accordance with a correcteddimming response.

The system of the present invention is particularly well suited forcommissioning fluorescent light fixtures in large public or privatebuildings where documentation for the operation of the large number oflight fixtures is required. The present invention has been described interms of specific embodiments incorporating details to facilitate theunderstanding of the principles of construction and operation of theinvention. As such, references, herein, to specific embodiments anddetails thereof are not intended to limit the scope of the claimsappended hereto. It will be apparent to those skilled in the art thatmodifications can be made in the embodiment chosen for illustrationwithout departing from the spirit and scope of the invention.

1. A portable device for commissioning light fixtures to provide atarget light level, the apparatus comprising: a) means for measuringlight values in a work plane of the light fixtures; and b) means forcommunicating, the means for communicating being configured for remotelyprogramming the light fixtures to automatically maintain light outputsat target values based on the light values measured.
 2. The portabledevice of claim 1, wherein the means for measuring the light valuescomprises a light sensor configured to measure illumination.
 3. Theportable device of claim 2, wherein the light sensor comprises one ormore light 2 emitting-diodes.
 4. The portable device of claim 1, whereinthe means for communicating comprises a wireless transceiver.
 5. Theportable device of claim 4, wherein the transceiver is an infraredtransceiver configured to provide two-way communication between theportable device a controller unit with a compatible infraredtransceiver, the controller unit being electrically couple to the lightfixtures.
 6. The portable device of claim 1, further comprising a powersource, the power source being selected from the group consisting of abattery and a solar cell.
 7. The portable device of claim 1, furthercomprising a user interface to allow a user to select the target valuesand initiate programming.
 8. The portable device of claim 1, furthercomprising a micro-processor and a data storage unit for runningsoftware to program the light fixtures and for storing program data. 9.The portable device of claim 1, further comprising means to transmitdata to a remote host computer.
 10. A system for managing lightfixtures, the system comprising: a) a controller unit coupled to thelight fixtures for regulating light outputs from the light fixtures inaccordance with a program; and b) a commissioning device configured toremotely program the controller unit to regulate the light outputsaccording to the program.
 11. The system of claim 10, wherein thecontroller unit comprises a photo-sensor for monitoring room light, andfurther wherein the controller unit is configured to regulate the lightoutputs based on a room light level.
 12. The system of claim 11, whereinthe light sensor is a photodiode with photopically correcting filters.13. The system of claim 10, wherein the controller unit comprises amicro-computer for running the program and for storing operating data.14. The system of claim 10, further comprising a wireless communicationmeans, wherein the commissioning device is configured to remotelyprogram the controller unit through the wireless communication means.15. The system of claim 14, wherein the wireless communication meanscomprises transceivers coupled to the commissioning device and thecontroller unit.
 16. The system of claim 10, wherein the commissioningdevice is configured to initiate a calibration sequence, wherein voltageinputs to the light fixtures are compared with light outputs from thelight fixtures to determine a correction factor for remotely programmingthe controller unit.
 17. The system of claim 10, further comprising anoverride device for overriding the controller unit and directlycontrolling light outputs from the light fixtures.
 18. The system ofclaim 17, wherein the override device is selected from the groupconsisting of a motion sensor and a manual switch.
 19. A method forcommissioning light fixtures, the method comprising: a) selecting atarget light level with a portable commissioning device; b) adjusting acontrol signal applied to the light fixtures such that light outputsmeet the target light level measured with the portable commissioningdevice; c) remotely programming a controller unit electrically coupledto the light fixtures to automatically maintain light outputs to meetthe target light level based on a light level measured with a controllerunit.
 20. The method of claim 19, wherein adjusting voltages applied tothe light fixtures comprises initiating a commission sequence from theportable commissioning device, whereby the portable commissioning deviceinstructs the controller unit to adjust voltages applied to the lightfixtures.
 21. The method of claim 19, wherein light outputs are measuredwith the portable commissioning device using a first light sensor. 22.The method of claim 21, wherein the light level measured with thecontroller unit uses a second light sensor.
 23. The method of claim 19,wherein remotely programming the controller unit comprises initiating acalibration sequence from the portable commissioning device, whereby theportable commissioning device instructs the controller unit to operatethe light fixtures over a range of applied voltages and measures thecorresponding light outputs using to determine a calibration factor.